move everything out of layout

core/src/widget/widgets.rs

@@ -0,0 +1,106 @@
+use crate::{
+    IdLike, Widget,
+    util::{DynBorrower, HashMap, HashSet, Id, IdTracker},
+};
+
+#[derive(Default)]
+pub struct Widgets {
+    pub updates: HashSet<Id>,
+    ids: IdTracker,
+    map: HashMap<Id, WidgetData>,
+}
+
+pub struct WidgetData {
+    pub widget: Box<dyn Widget>,
+    pub label: String,
+    /// dynamic borrow checking
+    pub borrowed: bool,
+}
+
+impl Widgets {
+    pub fn has_updates(&self) -> bool {
+        !self.updates.is_empty()
+    }
+
+    pub fn get_dyn(&self, id: Id) -> Option<&dyn Widget> {
+        Some(self.map.get(&id)?.widget.as_ref())
+    }
+
+    pub fn get_dyn_mut(&mut self, id: Id) -> Option<&mut dyn Widget> {
+        self.updates.insert(id);
+        Some(self.map.get_mut(&id)?.widget.as_mut())
+    }
+
+    /// get_dyn but dynamic borrow checking of widgets
+    /// lets you do recursive (tree) operations, like the painter does
+    pub fn get_dyn_dynamic(&self, id: Id) -> WidgetWrapper<'_> {
+        // SAFETY: must guarantee no other mutable references to this widget exist
+        // done through the borrow variable
+        #[allow(mutable_transmutes)]
+        let data = unsafe {
+            std::mem::transmute::<&WidgetData, &mut WidgetData>(self.map.get(&id).unwrap())
+        };
+        if data.borrowed {
+            panic!("tried to mutably borrow the same widget twice");
+        }
+        WidgetWrapper::new(data.widget.as_mut(), &mut data.borrowed)
+    }
+
+    pub fn get<I: IdLike>(&self, id: &I) -> Option<&I::Widget> {
+        self.get_dyn(id.id())?.as_any().downcast_ref()
+    }
+
+    pub fn get_mut<I: IdLike>(&mut self, id: &I) -> Option<&mut I::Widget> {
+        self.get_dyn_mut(id.id())?.as_any_mut().downcast_mut()
+    }
+
+    pub fn insert<W: Widget>(&mut self, id: Id, widget: W) {
+        let mut label = std::any::type_name::<W>().to_string();
+        if let (Some(first), Some(last)) = (label.find(":"), label.rfind(":")) {
+            label = label.split_at(first).0.to_string() + "::" + label.split_at(last + 1).1;
+        }
+        self.insert_any(id, Box::new(widget), label);
+    }
+
+    pub fn data(&self, id: &Id) -> Option<&WidgetData> {
+        self.map.get(id)
+    }
+
+    pub fn label(&self, id: &Id) -> &String {
+        &self.data(id).unwrap().label
+    }
+
+    pub fn data_mut(&mut self, id: &Id) -> Option<&mut WidgetData> {
+        self.map.get_mut(id)
+    }
+
+    pub fn insert_any(&mut self, id: Id, widget: Box<dyn Widget>, label: String) {
+        self.map.insert(
+            id,
+            WidgetData {
+                widget,
+                label,
+                borrowed: false,
+            },
+        );
+    }
+
+    pub fn delete(&mut self, id: Id) {
+        self.map.remove(&id);
+        self.ids.free(id);
+    }
+
+    pub fn reserve(&mut self) -> Id {
+        self.ids.next()
+    }
+
+    pub fn len(&self) -> usize {
+        self.map.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.map.is_empty()
+    }
+}
+
+pub type WidgetWrapper<'a> = DynBorrower<'a, dyn Widget>;